rodeo bucking

I've got a problem with my 92 rodeo 4wd 3.1 5 speed. when I let out the clutch in 1st gear from a dead stop the transmission seems like its going to jump out of the car. There is a very rough bucking from the rear and the shift knob about pulls out of my hand. I have: changed the clutch/pressure plate/ bearing.

3 new u-joints all mounts are good center support is solid new axle bearings All suggestions taken gladly accepted TIA Bill